One of my personal favorite road trips is the trip south out of Kona through the coffee belt and over to the active volcano on the Big Island.
If you head out south on Hwy 11, you will first come to Keauhou which has a nice marketplace shopping center and the bay from which several snorkel tours depart.
The next point of interest will be Kona Joe's and a bit further down the road, Greenwell Farms. Both are premium coffee producers, offering visitors tours and purchasing opportunities for 100% Kona coffee. Our preference is for Greenwell Farms on two counts . . . wonderful coffee and free tours. Kona Joe's currently charges $15 per person, but in fairness, you do receive a "free" souvenir coffee mug. There is also a coffee heritage museum near Greenwell Farms, which is also worth a visit if they are open when you are in this area.
There is outstanding snorkeling at the area known as "Two Step" by the Pu'uhonua o Honaunau National Historical Park (aka Place of Refuge). While not "easy" the entry from the lava rocks is possible. The views beneath the water's surface is worth it!
Continuing on the next special place is South Point which requires an approximate 10 mile trip from Hwy 11 on a paved, but rough road. The views of the sheer cliffs are special, and shouldn't be missed. This is the southernmost spot in the entire USA. Key West has a spot that is the southernmost on the contiguous 48.
Next stop is the Punalu'u Bakery. Get here early, however, or else you'll have slim pickins. We arrived at around 2:30pm and were disappointed and passed on buying a mid-afternoon snack.
The black sand beach of Punalu'u State Park is an almost sure thing for turtles. I say "almost" as I've been here six or seven times and have only missed seeing turtles once. This beach area is a nice place for a picnic lunch, but not so inviting if beach swimming is on your agenda.
Next stop will be Hawaii Volcanoes Nat'l Park. By this point, you have traveled approximately 100 miles and roughly 2.5 to 3 hours depending on stops. If you arrive early enough in the afternoon, allow yourself a couple of hours of daylight to visit the two visitors centers and travel the park road(s). Be prepared, however, as the current lava eruption has much of the road system closed.
For us, we continued on after the park to go to the public viewing area down Hwy 130 which is roughly another hour away (towards Hilo). This was a highlight of our vacation, however, as once the sun set (7p) we were treated to a nice view of the lava flowing down the hillside at several spots. The viewing area where we stood just a week ago, has since been completed covered over by four feet of lava so be aware that this is an ever changing area of the island. You will want to check with the National Park Service on the current conditions with the lava flow as well as the USGS info which is provided on the areas outside of the park itself.
After a full day of touring, we headed back to our timeshare. Plan on a three hour non-stop drive. The road is narrow in some spots and very dark throughout. Allow plenty of time and be careful as it will be easy to become tired on the trip back to Kona.
A word about buying gas . . . prices in Kona were consistently $3.93 to $3.99 but up between Volcanoes NP and Hilo it was $3.55 to $3.59. This was the cheapest gas that we saw on the island. We tanked up every time we saw cheaper gas before heading back to Kona!
Be sure to take along snacks and water, as well as a flashlight for each person visiting the lava viewing area. Additionally, be prepared for a bit of a walk so good sneakers or walking shoes are a must. You'll want to be prepared for rain and cool evening temps, so dress (or be ready to dress) in layers.
Roundtrip, you can expect to drive approximately 250-280 miles.